Cost to Reshingle Roof

[Jordan Decuir]

I am under contract to purchase a single family in The Houston area. The existing asphault shingles are weathered and worn, some shingles are missing entirely, what is the estmated range of cost to reshingle the entire roof? We have been in the attic and there are no signs of water coming through the roof, i.e. there are no water spots or discoloration on the plywood, so I believe that we are talking about just replacing all of the shingles. I reached out to some roofers and hope to get quotes today and tomorrow, but I am looking to use the wealth of knowledge available from fellow BPer's to get an idea of the cost. 

The home was built in 1984, is a single story, 1545 square feet, and the roof does not have a particularly steep pitch (slope). 

Jordan